This invention relates generally to mammography biopsy systems that are designed to detect and obtain cell or tissue samples from non-palpable lesions of the female breast. More particularly, this invention is directed to an advanced mammographic needle biopsy system incorporating a motorized biopsy needle positioner that automatically positions a biopsy needle to allow insertion to an identified point of interest in a patient's breast that is under examination.
Mammographic needle biopsy systems, such as a Mammotest system manufactured and marketed by Fischer Imaging Corporation, Denver, Colo., employ a computer-digitizer system to digitize the location of a point of interest within the patient's breast as that point of interest appears on a pair of stereo x-rays of the breast and to thereafter compute the three-dimensional or spatial coordinates of that point of interest and display them to the user. The user then manually sets these three-dimensional coordinates into respective position controls for a puncture instrument assembly and inserts a biopsy or other needle to the identified point of interest. These manual systems are susceptible to human error in setting the computed coordinates of the point of interest into the puncture instrument. In addition, manual setting of the coordinates of the point of interest is a time consuming operation that is frustrating to the patient, who is required to continue holding a position in which one of her breasts is under compression. Also, the clinician user is not permitted the flexibility of inserting the biopsy needle to a point within the patient's breast that is slightly offset from the previously identified point of interest because the coordinates provided by the computer-digitizer correspond only to the identified point of interest. It will be appreciated that such offset insertion in the present invention facilitates multiple pass sampling of a breast lesion using a driven biopsy instrument or other biopsy instrument as may be desired.